Light control film (LCF), also known as light collimating film, is an optical film that is configured to regulate the transmission of light. Various LCFs are known, and typically include a light transmissive film having a plurality of parallel grooves wherein the grooves are formed of a light-absorbing material.
LCFs can be placed proximate a display surface, image surface, or other surface to be viewed. At normal incidence, (i.e. 0 degree viewing angle) where a viewer is looking at an image through the LCF in a direction that is perpendicular to the film surface, the image is viewable. As the viewing angle increases, the amount of light transmitted through the LCF decreases until a viewing cutoff angle is reached where substantially all the light is blocked by the light-absorbing material and the image is no longer viewable. This can provide privacy to a viewer by blocking observation by others that are outside a typical range of viewing angles.
LCFs can be prepared by molding and ultraviolet radiation curing a polymerizable resin on a polycarbonate substrate. Such LCFs are commercially available from 3M Company, St. Paul, Minn., under the trade designation “3M™ Filters for Notebook Computers and LCD Monitors”.
Advances in display technology have resulted in brighter, higher resolution and more energy efficient displays that consumers want. The brightness and resolution of a display can be reduced when an LCF is positioned in front of the display for security or other purposes. It would be desirable to have an LCF which does not reduce the brightness and resolution of a display.